1. Field of the Invention
The invention relates to a panel, more particularly, relates to a touch panel and a touch display panel.
2. Description of Related Art
Based on different ways of sensing, touch panels are generally categorized into resistant touch panels, capacitive touch panels, optical touch panels, sonic wave touch panels, and electromagnetic touch panels. The configurations of touch panels and display panels may further classify the touch panels into an add-on type and an in-cell type. Touch devices are often formed on a substrate to make the touch panel, and the touch panel is then attached to an outer surface of a display panel. This is the so-called add-on type touch panel. By contrast, the in-cell touch panel is formed by directly integrating the touch devices into the display panel.
In the existing in-cell touch panel structure, fan-out lines extending from a sensing region to a peripheral region may result in the peripheral region with an uneven surface. To solve this problem, an overcoat layer is often formed on the color filter side, such that sealant may be distributed on a relatively even surface. Thereby, if a pixel array substrate and a color filter substrate are assembled, an around-gap-mura problem caused by the uneven surface of a visible region may not occur.
Nonetheless, the overcoat layer is usually made of an organic material that is apt to absorb moisture; therefore, in an assembly process or the like manufacturing process, moisture may be released due to heat. As such, the moisture-containing liquid crystal layer may result in the around-gap-mura problem in the panel.